This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. As artificial pancreas systems are tested in hospital settings and eventually in field conditions, it becomes apparent that such systems suffer from ample glucose excursions, both in hypoglycemia and hyperglycemia. The need for supervisory systems that prevent such large glucose variation rise from the incapacity of modern controllers to properly adapt and react to very high and/or very low glucose, and the resulting qualitative metabolic changes (e.g. counter-regulation and gluco-toxicity). Such supervisory systems, called controllers to range, are not aiming at perfect glucose control (i.e. glucose variations comparable to health) but at mitigating large glucose deviations, keeping the patient safe and create the environment for more precise control strategies to function optimally. This protocol is designed to demonstrate the feasibility in a GCRC setting of such a supervisory system during different metabolic conditions, such as meals, mild exercise and sleep. Our system is based on continuous monitoring and subcutaneous insulin injections, and monitors the patient's regular treatment, i.e. unless an error in treatment is detected (glucose going low or high) the system will stay inactive. Performances of the system will be assessed using frequency of hypoglycemic events and amount of time spent in a wide glucose target range.